[Rick Dangerous]

The #1 piece of information i want on a motorcycle is when i'm about to hit redline so i can shift; yet i notice less and less new bikes have them.  WHY?!

I've been told "well you just sort of listen and feel the powerband and you'll know when to shift". Uh...no thanks, i want to know to the hundredth of an RPM thank you very much.

So many bikes I won't consider because they no longer include tacho's.  What is going on here?

[AzCal Retred]

Which bikes are you specifically concerned with? There are a bewildering variety of sub-$50 add-on electronic tachometers available. Don't let lack of a tach stop a good deal from happening. Unless it makes real horsepower and turns some actual RPM, there's no point - just chuff along & "use the Force"! 
Redlines are a suggestion anyway, just telling you when the "fuse" starts burning. The longer you spend there the more it'll cost later. OR, get a nice used Hayabusa or ZX14, the red line will likely not see a lot of use. When trying to force 180 HP thru maybe 20 square inches of contact patch, the pucker on the seat will likely let you know when it's "enough"!

[Karl Childers]

Personally I'd rather have a tachometer than ABS or traction control but I'm old fashion. Possibly it is due to the current wave of customers being so disassociated from the mechanical aspect of motorcycles as to render it meaningless. Maybe calling it an "RPM App"  and have it accessed from your phone may generate some interest.

[zimmemr]

The #1 piece of information i want on a motorcycle is when i'm about to hit redline so i can shift; yet i notice less and less new bikes have them.  WHY?!

I've been told "well you just sort of listen and feel the powerband and you'll know when to shift". Uh...no thanks, i want to know to the hundredth of an RPM thank you very much.

So many bikes I won't consider because they no longer include tacho's.  What is going on here?

A tach is useful, but there's an awful lot of race bikes that don't use them and the riders seem to wring all the power out of them their engines can muster without knowing where a needle is pointing.  I think that even on race bikes that do use them, mostly road racers and some drag bikes, you'll find the riders don't pay all that much attention to them.

I'd also suggest that if you're running to redline in every gear before shifting, you're basically running into the "empty rev" zone which wastes time and power and can be hard on the motor. Learn to shift when the torque peak drops off, which is always some hundred(s) of rpm before red line, (in some cases 1,000(s)) and you and the bike will be better off for it.

[Rick Dangerous]

Personally I'd rather have a tachometer than ABS or traction control but I'm old fashion. Possibly it is due to the current wave of customers being so disassociated from the mechanical aspect of motorcycles as to render it meaningless. Maybe calling it an "RPM App"  and have it accessed from your phone may generate some interest.

100%.  Totally indifferent to ABS/Traction control; just let me see my revs already!

Lots of Moto-guzzi, Ducati, Indian, Triumph, etc. bikes no longer come with a tach that had them on similar models 10 years ago or less.  Or you only see them on "special" models these days.  You would think it would be a pretty important thing to have on a vehicle with a manual transmission.   A ton of bikes are "single gauge" these days.  I can't stand digital gauges either but thats a story for another thread i guess.

[viczena]

Tachs are quite uninteresting. After a short while you hear/feel if the bike runs right.

An excemption would be a  high rev bike without rpm limiter.

[NVDucati]

snip
So many bikes I won't consider because they no longer include tacho's.  What is going on here?

In a hyphenated word; rev-limiters.
That plus folks who use programmable ECUs you can adjust where exactly the rev-limiter kicks in.
But I completely agree with you about wanting a tach. I think that if I want a particular bike that doesn't come one ... I'd buy an induction tach. They are very affordable and accurate. You can choose whatever style/size display you want.
One of a giddle choices comes with 7 colors of faces for $35.
https://www.amazon.com/SREUOIL-52mm-Tachometer-Tacho-Gauge-Smoke-Face-Color-Tinted-Meter-0-8000-RPM-Cylinder/dp/B09D3Q7NVB/ref=sr_1_1_sspa?crid=UW7HCOZFV9XS&keywords=SREUOIL+52mm+Tachometer+2%22+Tacho&qid=1642531281&sprefix=sreuoil+52mm+tachometer+2+tacho%2Caps%2C330&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzUDFaU1BPS01KNzNCJmVuY3J5cHRlZElkPUEwMDcyNTkxMUlZMjNVOFFKRVRDNCZlbmNyeXB0ZWRBZElkPUEwMjYyODg0N1c3TFpROE9YSDRIJndpZGdldE5hbWU9c3BfYXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

[zimmemr]

100%.  Totally indifferent to ABS/Traction control; just let me see my revs already!

Lots of Moto-guzzi, Ducati, Indian, Triumph, etc. bikes no longer come with a tach that had them on similar models 10 years ago or less.  Or you only see them on "special" models these days.  You would think it would be a pretty important thing to have on a vehicle with a manual transmission.   A ton of bikes are "single gauge" these days.  I can't stand digital gauges either but thats a story for another thread i guess.

For the sake of conversation that was just as true 30, 40 or 50 years ago. Back in the day a tach was often used to denote a "sporting" version of a bike. For example, the single carb/low compression BSA 650 Thunderbolt had only a speedometer while it's sportier brothers the Lightening and Spitfire to name just two came with both instruments. Likewise, the Harley Sportster, the hot rod CH came with a tach while the more sedate H model had only a speedo. BMW /2's only offered them as options no matter what you bought. I'd offer it was the influx of Japanese bikes in the 60's, many of which came with tachs, that made them a standard fitment. 

[Keef Sparrow]

I think virtually all modern bikes have had rev limiters for many years now, and they largely make rev counters obsolete as you can't over rev the bike even if you try.

[Karl Childers]

Take a look at a dynometer chart for either your stock or modified bike and you will see where the torque and horsepower curve intersect and that's you motor's sweet spot, yeah the seat of your pants will kind of tell but a tach tells you right where you're at and I find that useful on day rides with my more modern motorcycles that have six speeds and I'm out in the country cruising at 80 mph I know exactly what rpm I'm at and not lugging it or over revving it in 5th and 6th gear. the seat of the pants and your ear are not the most reliable gauge in an 80 mph wind blast. Then there is the rev limiter, yes it will keep you from floating your valves and worse but then there's the passing cars on a short straight away scenario. You pull out whack the throttle and get by as quick as you can before another car comes the other way only you start bouncing off the rev limiter because you should have upshifted one more time. A quick glance at the tach would would have told the story but without it you're bouncing off the limiter in the passing lane losing momentum with a car coming. To me a tach is very much a nicety in those situations. My Harley will pull a pass in one gear my Beemer doesn't come on the cam until 6,000 rpm and then it's a short hop to redline and always takes two gears  for a slingshot pass and the shift point is critical.

I even have a tach in my old 300cu. in six cylinder Ford pick up. All the power in that motor is at 2,500 rpms or less anything more is a waste of fuel  and adds wear and tear, if you know your engine a tach is a useful tool to have.

[GlennF]

I think virtually all modern bikes have had rev limiters for many years now, and they largely make rev counters obsolete as you can't over rev the bike even if you try.

This is the main reason and a good thing. Accidently going 1500 rpm over the red line on a missed shift on older bikes never gave a good feeling.

As far as watching the tacho to know when to shift, I heard it said once that all that does is distract your attention from the road and you really should know your bike well enough to shift at the optimal point while watching the road not the tacho.

[Richard230]

This is the main reason and a good thing. Accidently going 1500 rpm over the red line on a missed shift on older bikes never gave a good feeling.

As far as watching the tacho to know when to shift, I heard it said once that all that does is distract your attention from the road and you really should know your bike well enough to shift at the optimal point while watching the road not the tacho.

With my 1964 Honda CB305 Super Hawk, going over the 9,200 rpm red line by 1 rpm would cause the valves to float. 

[AzCal Retred]

I'm with Keef, Zim & NVD here, riding by feel can get you around a race track plenty fast. The random environment of the street needs more "survival" and less "go fast" mindset. I'm sure an Expert level rider will always out-ride the average guy even if you duct tape over his tach.

An old school high-angle, 2-heavy-valves-design motor is way more likely to tangle its valves or float them into a piston crown than current design 4 & 5 valve, low-angle motors. Electronic ignition rev limiters keep you out of the factory float zone unless over-ridden by the owner-tuner-tinkerer. If you still feel left out, tachs are a cheap & easy recreational add on.
 
If you are regularly wringing out a (non-desmo!) 2-valve motor, there's lots of pricey bits need to be added to assure the valves are actually following the cam profile accurately & avoiding the piston. Or just get something used with actual horsepower, like a Hayabusa/ZX14 & get it out of your system...probably cheaper in the long run. I doubt you'll spend much time exploring its 11K+ redline.   My experience is that a 2-lane highway gets pretty narrow over 100 MPH, let alone 180.

[Karl Childers]

Riding fast on the street and racing are two very different things. You won't find a tach on a flat tracker for example because racing is all about pushing your bike to the just this side of the limit mechanically and staying ahead of the guy who is trying to pass you, if your bike holds together you win if not you blow the motor and either your sponsor has your pit crew put the spare motor in for the next heat or if you're a privateer you're up shitz creek and scrambling to get your bike ready for next week because you are out of it for this one. That's why there's no tachs on flat trackers or motocross bikes, it's balls to the wall. Hang around the track long enough and you will always hear "Man the bike was running sweeter than it ever did just before the motor blew up". Endurance racing and moto GP involves a different strategy, the races are longer and you're just nursing it along in the top three until final few laps and then the same thing comes into play, if you haven't used your tires up you pull out all the stops and go for it, there's very little sympathy for the machinery at that point. I've owned some fast cafe racers and sport bikes, have been faster than most guys I know yet was never afraid to take a glance at my tach no matter how fast I was going, there's an advantage to knowing what your motor is doing especially when you don't have deep pockets to fix it every week and I still left everyone in my dust.



I

[AzCal Retred]

Top three is pretty rarified turf. If you're "you're just nursing it along in the top three" that says a lot about your basic skill set!   

Desert racers routinely run 90 to 120+ miles at 80% - 90% race pace with no tachs. Some open jeep road sections are 80 MPH or better on knobbies for a few miles. Fast guys will always go fast, I've found. A skilled, disciplined rider that has some mechanical sympathy has a far better chance of finishing, & placing/winning in an endurance event than a "wildcat" rider. Undisciplined wild riders can break anything, either by crashing or mechanical abuse.   

A tach informs you but doesn't affect your skill level. A tach can obviously be a great tool if you are routinely "pushing it" to redline levels to maximize HP & acceleration, but my point was that if you have plenty of HP on tap (Hayabusa/ZX14) you are likely not going to be glued to the redline looking for more. Spending the engine's service life at redline shortens that life, and as speed generally equals HP, going fast on a higher HP machine is easier on the engine. Maybe not so much for the tires, brakes & rider, but with real HP on tap the engine doesn't need to work at maximum effort nearly as much. On a track where everyone's likely on the same displacement level, high RPMs are a forgone conclusion. On the street, unless you have the "deep pockets" for regular rebuilds, more cubes is probably a better long term solution than continuous high RPM.